<template>
  <div id="container"> 
    <!-- 上一页、下一页 -->
    <div class="right-btn">
      <!-- 输入页码 -->
      <div class="pageNum">
        <input
          v-model.number="currentPage"
          type="number"
          class="inputNumber"
          @input="inputEvent()"
        />
        / {{ pageCount }}
      </div>
      <div @click="changePdfPage('first')" class="turn">首页</div>
      <!-- 在按钮不符合条件时禁用 -->
      <div
        @click="changePdfPage('pre')"
        class="turn-btn"
        :style="currentPage === 1 ? 'cursor: not-allowed;' : ''"
      >
        上一页
      </div>
      <div
        @click="changePdfPage('next')"
        class="turn-btn"
        :style="currentPage === pageCount ? 'cursor: not-allowed;' : ''"
      >
        下一页
      </div>
      <div @click="changePdfPage('last')" class="turn">尾页</div>
    </div>
    <div class="pdfArea">
      <pdf
        :src="src"
        ref="pdf"
        v-show="loadedRatio === 1"
        :page="currentPage"
        @num-pages="pageCount = $event"
        @progress="loadedRatio = $event"
        @page-loaded="currentPage = $event"
        @loaded="loadPdfHandler"
        @link-clicked="currentPage = $event"
        style="display: inline-block; width: 100%"
        id="pdfID"
      ></pdf>
    </div>
    <!-- 加载未完成时，展示进度条组件并计算进度 -->
    <div class="progress" v-show="loadedRatio !== 1">
      <el-progress
        type="circle"
        :width="70"
        color="#53a7ff"
        :percentage="Math.floor(loadedRatio * 100)"
      ></el-progress
      ><br /><!-- 加载提示语 --><span>{{ remindShow }}</span>
    </div>
  </div>
</template><script>
import pdf from "vue-pdf";
export default {
  components: { pdf },
  props: {
    pdfUrl: {
      type: String,
      default: "",
    },
    recordId: {
      type: String,
      default: "",
    },
  },
  computed: {},
  created() {
    this.src = this.pdfUrl;
    this.key = this.recordId;
    this.prohibit();
  },
  destroyed() {
    // 在页面销毁时记得清空setInterval
    clearInterval(this.intervalID);
  },
  mounted() {
    // 更改 loading 文字
    this.intervalID = setInterval(() => {
      this.remindShow === this.remindText.refresh
        ? (this.remindShow = this.remindText.loading)
        : (this.remindShow = this.remindText.refresh);
    }, 4000); // 监听滚动条事件
    this.listenerFunction();
  },
  data() {
    return {
      // ----- loading -----
      remindText: {
        loading: "加载文件中，文件较大请耐心等待...",
        refresh: "若卡住不动，可刷新页面重新加载...",
      },
      remindShow: "加载文件中，文件较大请耐心等待...",
      intervalID: "", // ----- vuepdf -----
      // src静态路径: /static/xxx.pdf
      // src服务器路径: 'http://.../xxx.pdf'
      src: "",
      // 当前页数
      currentPage: 0,
      // 总页数
      pageCount: 0,
      // 加载进度
      loadedRatio: 0,
      key:'',
    };
  },
  methods: {
    // 监听滚动条事件
    listenerFunction(e) {
      document.getElementById("container").addEventListener("scroll", true);
    },
    // 页面回到顶部
    toTop() {
      document.getElementById("container").scrollTop = 0;
    },
     // 输入页码时校验
    inputEvent() {
      if (this.currentPage > this.pageCount) {
        // 1. 大于
        maxthis.currentPage = this.pageCount;
      } else if (this.currentPage < 1) {
        // 2. 小于
        minthis.currentPage = 1;
      }
    },
    // 切换页数
    changePdfPage(val) {
      if (val === "pre" && this.currentPage > 1) {
        // 切换后页面回到顶部
        this.currentPage--;
        this.toTop();
      } else if (val === "next" && this.currentPage < this.pageCount) {
        this.currentPage++;
        this.toTop();
      } else if (val === "first") {
        this.currentPage = 1;
        this.toTop();
      } else if (val === "last" && this.currentPage < this.pageCount) {
        this.currentPage = this.pageCount
        this.toTop();
      }
       window.localStorage.setItem("pdf-view-curpage-" + this.key, this.currentPage);
    },
    goTo(val) {
      this.currentPage = val;
      this.toTop();
    },
    // pdf加载时
    loadPdfHandler(e) { 
      var pdfViewCurpage = window.localStorage.getItem(
        "pdf-view-curpage-" + this.key
      );
      if (pdfViewCurpage) {
        this.currentPage = Number(pdfViewCurpage);
      }else{
         // 加载的时候先加载第一页 
         this.currentPage = 1;
      } 
    },
    // 禁用鼠标右击、F12 来禁止打印和打开调试工具
    prohibit() {
      return
      // console.log(document)
      document.oncontextmenu = function () {
        return false;
      };
      document.onkeydown = function (e) {
        if (
          e.ctrlKey &&
          (e.keyCode === 65 ||
            e.keyCode === 67 ||
            e.keyCode === 73 ||
            e.keyCode === 74 ||
            e.keyCode === 80 ||
            e.keyCode === 83 ||
            e.keyCode === 85 ||
            e.keyCode === 86 ||
            e.keyCode === 117)
        ) {
          return false;
        }
        if (e.keyCode === 18 || e.keyCode === 123) {
          return false;
        }
      };
    },
  },
};
</script>
<style scoped>
#container {
  overflow: auto;
  height: 800px;
  font-family: PingFang SC;
  width: 100%;
  display: flex; /* justify-content: center; */
  position: relative;
  border: 1px solid #eee;
} /* 右侧功能按钮区 */
.right-btn {
  position: fixed;
  right: 5%;
  bottom: 15%;
  width: 120px;
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  z-index: 99;
}
.pdfArea {
  width: 80%;
  margin: 0 auto;
} /* ------------------- 输入页码 ------------------- */
.pageNum {
  margin: 10px 0;
  font-size: 18px;
}
/*在谷歌下移除input[number]的上下箭头*/
input::-webkit-outer-spin-button,
input::-webkit-inner-spin-button {
  -webkit-appearance: none !important;
  margin: 0;
}
/*在firefox下移除input[number]的上下箭头*/
input[type="number"] {
  -moz-appearance: textfield;
}
.inputNumber {
  border-radius: 8px;
  border: 1px solid #999999;
  height: 35px;
  font-size: 18px;
  width: 60px;
  text-align: center;
}
.inputNumber:focus {
  border: 1px solid #00aeff;
  background-color: rgba(18, 163, 230, 0.096);
  outline: none;
  transition: 0.2s;
} /* ------------------- 切换页码 ------------------- */
.turn {
  background-color: #888888;
  opacity: 0.7;
  color: #ffffff;
  height: 70px;
  width: 70px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 5px 0;
}
.turn-btn {
  background-color: #000000;
  opacity: 0.6;
  color: #ffffff;
  height: 70px;
  width: 70px;
  border-radius: 50%;
  margin: 5px 0;
  display: flex;
  align-items: center;
  justify-content: center;
}
.turn-btn:hover,
.turn:hover {
  transition: 0.3s;
  opacity: 0.5;
  cursor: pointer;
} /* ------------------- 进度条 ------------------- */
.progress {
  position: absolute;
  right: 40%;
  top: 40%;
  text-align: center;
}
.progress > span {
  color: #199edb;
  font-size: 14px;
}
</style>